1. Field of the Invention
The present invention generally relates to motorized vehicles, and more particularly to concrete power buggies.
2. Background Information
As disclosed in U.S. Pat. No. 4,645,264, the teachings of which are hereby incorporated by reference, concrete construction and other work requiring on-the-job transport of heavy materials from one location to another has brought about the development of a variety of relatively-small, load-carrying vehicles capable of moving on the job site with relatively small but often very heavy loads of material. For example, a frequent need is to load a quantity of concrete at a first location, transport such concrete to a second location and then dump the contents for spreading and screeding operations at the second location.
In concrete work, such a vehicle is often referred to as a xe2x80x9cconcrete buggy.xe2x80x9d Such vehicles may also be referred to as a dump truck or power-driven wheelbarrow. Some of such vehicles are of the walk-behind type while others are of the step or seat-riding type. The load which is carried by a container called a xe2x80x9cskip,xe2x80x9d xe2x80x9chopper,xe2x80x9d xe2x80x9cpan,xe2x80x9d or xe2x80x9cdump boxxe2x80x9d is conventionally raised and lowered by a hydraulic piston as in U.S. Pat. Nos. 2,424,670 or 2,427,132. A front pair of single or dual wheels is conventionally driven by a differential and transmission as in U.S. Pat. No. 2,427,132.
Other vehicles have trinary wheel means wherein two separate front wheel means each having single or dual wheels proceed a solitary single or dual rear wheeled means. Typically, the solitary wheeled means supports the rear of the vehicle and is adapted for rotating around a vertical axis for the purpose of steering the vehicle and sometimes with use of a steering mechanism as in U.S. Pat. No. 2,427,132, while the front wheel means supports the front of the vehicle. The trinary-type vehicle is also shown in U.S. Pat. Nos. 4,986,387 and Re. 333,131. Other patents describe vehicles with trinary wheel means having a powered solitary rear wheel means, including U.S. Pat. No. 2,674,328 (Searls), U.S. Pat. No. 2,820,524 (Bear), U.S. Pat. No. 2,942,677 (Gray), and U.S. Pat. No. 3,826,326 (Blair).
However, none of these patents describe a motorized dump-type vehicle having powered front wheels and the ability to engage the vehicle""s rear wheel(s) when needed for added traction or control.
A concrete buggy which is filled with concrete tends to have a center of gravity shifted towards the center of the vehicle, towards the front wheels of the buggy. After the buggy dumps its load of concrete, this center of gravity shifts rearward, towards the rear wheel(s) and engine of the buggy. This shift of the center of gravity leaves the front end light, occasionally causing problems in getting traction with the front wheels, particularly where the soil is wet, loose or sandy. This is particularly so in situations where the front drive wheels of the buggy sink into mud when loaded, and after dumping have insufficient traction to climb back out of the ruts so formed.
It is one object of the present invention to provide a motorized dump-type vehicle for on-the-job transporting of concrete or other materials, the vehicle having at least two powered front wheels and the ability to power at least one rear wheel for added traction and control, as needed.
Additional objects, advantages and novel features of the invention will be set forth in part in the description as follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
The present invention is a motorized dump-type vehicle for on-the-job transporting of concrete or other materials. The preferred embodiment of the present invention has a chassis frame having front and rear ends, and left and right sides. An engine is mounted near the rear end of the frame.
At least one front hydraulic drive means is secured to the frame, preferably near the front end of the frame. The vehicle has a left wheel means located on the left side of the frame front end. This left wheel means is drivingly connected to at least one front hydraulic drive means thereby enabling the left wheel to be driven. The vehicle also has a right wheel means located on the right side of the frame front end. The right wheel means is drivingly connected to at least one front hydraulic drive means thereby enabling the right wheel means to be driven.
The vehicle has an attached open top dump container. This container is preferably supported on the frame and has a bottom front end portion which is pivotally mounted on the front end of the frame. The vehicle has at least one hydraulic piston/cylinder having one end pivotally mounted on the frame and the opposite end pivotally connected to the container thereby enabling the rear end of the container to be raised and lowered.
The vehicle further has at least one rear hydraulic drive means secured to the frame, preferably at the rear end of the frame. At least one rear wheel means is preferably mounted below and centrally of the rear end of the frame, thereby enabling the rear wheel means to swivel about a vertical axis for steering the vehicle. The rear wheel means is drivingly connected to the rear hydraulic drive means thereby enabling the rear wheel means to be driven.
The vehicle further has a hydraulic fluid tank. This tank has an input connection for receiving and storing hydraulic fluid and an output connection for withdrawing fluid to be pumped. An adjustable oil pump is additionally mounted on the vehicle frame and drivingly connected to said engine, this pump having a pump input connection to the output connection of the tank and a pump output connection.
Finally, the vehicle further has a hydraulic valve and conduit system connected between the pump output connection and the tank input connection including a first lever-controlled valve connected by conduit to the piston/cylinder for raising and lowering the container, second lever-controlled valve connected by conduit to the front hydraulic drive means for forward and reverse driving of the left and right wheels, and a third lever-controlled valve connected by conduit to the rear hydraulic drive means for engaging or disengaging the rear wheel means.